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April 19, 2016

Large Hadron Collider results may hint at a new era of physics

Filed under: Big Bang, Black Holes, Cool, Wierd — bferrari @ 2:00 pm
The LHC (Large Hadron Collider) tunnel. (REUTERS/Denis Balibouse)

The LHC (Large Hadron Collider) tunnel. (REUTERS/Denis Balibouse)

Are we about to enter a new era of physics?  Data collected by the Large Hadron Collider in Switzerland may have identified particle activity that doesn’t fit the standard laws of physics.

The analysis by scientists including physicists at the Institute of Nuclear Physics at the Polish Academy of Sciences (IFJ PAN) could have huge scientific implications.

“There are some indications that physicists working at the LHC accelerator at the European Organization for Nuclear Research (CERN) near Geneva may see the first traces of physics beyond the current theory which describes the structure of matter,” said the IFJ PAN, in a recent press release.

The structure of matter is described by a theoretical framework called The Standard Model, which identifies the roles played by different particles. Boson particles, for example, are carriers of forces, whereas photons are related to electromagnetic interactions. Matter is formed by particles called fermions.

However, scientists, analyzing data collected by the LHCb experiment in 2011 and 2012, noticed an anomaly in the decay of a particle called a B Meson. According to the research, the traditional method for determining the particle’s decay may lead to false results.

Related: Science breakthrough? Physicists may have discovered Higgs boson relative

Could the anomaly hint at a new understanding of the Universe? Scientists are certainly intrigued by the anomaly. To put it in terms of the cinema, where we once only had a few leaked scenes from an much-anticipated blockbuster, the LHC has finally treated fans to the first real trailer,” said Professor Mariusz Witek of IFJ PAN, in the release.

Witek notes that the framework used to describe the structure of matter poses plenty of questions for scientists. “The Standard Model cannot explain all the features of the Universe,” he said. “It doesn’t predict the masses of particles or tell us why fermions are organized in three families. How did the dominance of matter over antimatter in the universe come about? What is dark matter? Those questions remain unanswered.”

To further illustrate his point, the Professor notes that gravity isn’t even included in the Standard Model.

However, scientists caution that more research is needed on the B Meson anomaly. “We can’t call it a discovery. Not yet,” said the IFJ PAN.

CERN spokesman Arnaud Marsollier told FoxNews.com that the B Meson data, which first emerged last year, are not conclusive. “More data are needed before we can tell anything significant on this, so we will have to wait for the LHC to restart (soon),” he explained via email, noting the importance of patience when recording and analyzing data. “Science needs time!” he added.

Related: Revamped Large Hadron Collider set to restart

CERN is currently starting powering tests on the huge particle accelerator. “Beams should be back by the end of the month or early April, and collisions sometimes next month if everything goes as planned,” said Marsollier.

Oxford University Physics Professor Guy Wilkinson, who serves as the spokesman for the LHCb experiment, told FoxNews.com that CERN’s B Meson data is “extremely interesting,” but noted that it could be a couple of years before scientists perform a full analysis. “When we analyse this new sample in a year or two we will be able to make a fresh and, I hope, more categorical statement on this topic,” he explained, via email.

The 17-mile LHC was built between 1998 and 2008 to help scientists test some theories of particle and high-energy physics and advance understanding of physical laws.

In 2012 the Collider won global acclaim with the discovery of the long-sought Higgs boson  particle, which explains the behavior of other particles. Physicists Peter Higgs and Francois Englert were subsequently awarded the 2013 Nobel Prize in Physics.

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February 11, 2016

Scientists find evidence of gravitational waves predicted by Einstein

Filed under: Big Bang, Black Holes, Cool, Cosmology, Gamma Ray Bursts — bferrari @ 11:54 am
File image - An image from a simulation showing how matter might be moved around in the extreme environment around a black hole. (Özel/Chan) (Özel/Chan)

File image – An image from a simulation showing how matter might be moved around in the extreme environment around a black hole. (Özel/Chan) (Özel/Chan)

After decades of searching, scientists announced Thursday that they have detected gravitational waves which are ripples in the fabric of space-time that were predicted by Einstein.

 

An international team of astrophysicist said that they detected the waves from the distant crash of two black holes, using a $1.1 billion instrument. The Ligo Collaboration was behind the discovery and it has been accepted for publication in the journal Physical Review Letters.

Related: Meteorite probably didn’t kill man in India, NASA says

“We have detected gravitational waves,” Caltech’s David H. Reitze, executive director of the LIGO Laboratory, told journalists at a news conference in Washington DC.

The news, according to the Associated Press, is being compared by at least one theorist to Galileo taking up a telescope and looking at the planets and the biggest discovery since the discovery of the Higgs particle. It has stunned the world of physics and astronomy, prompting scientists to say it the beginning of a new era in physics that could lead to scores more astrophysical discoveries and the exploration of the warped side of the universe.

“Our observation of gravitational waves accomplishes an ambitious goal set out over five decades ago to directly detect this elusive phenomenon and better understand the universe, and, fittingly, fulfills Einstein’s legacy on the 100th anniversary of his general theory of relativity,” Reitze said in a statement.

Related: Hundreds of hidden galaxies glimpsed behind Milky Way

The discovery confirms a major prediction of Albert Einstein’s 1915 general theory of relativity. Gravitation waves carry information about their dramatic origins and about the nature of gravity that cannot be obtained from elsewhere.

Not only have they fascinated by scientist by found their way into pop culture – namely through movies such as “Back To The Future,” where the space-time continuum was used a medium for the DeLorean time machine to go back in time. It also featured in the “Terminator” series.

Their existence was first demonstrated in the 1970s and 1980s by Joseph Taylor, Jr., and colleagues. In 1974, Taylor and Russell Hulse discovered a binary system composed of a pulsar in orbit around a neutron star. Taylor and Joel M. Weisberg in 1982 found that the orbit of the pulsar was slowly shrinking over time because of the release of energy in the form of gravitational waves. For discovering the pulsar and showing that it would make possible this particular gravitational wave measurement, Hulse and Taylor were awarded the 1993 Nobel Prize in Physics.

Related: White House proposes $19 billion NASA budget

In the latest breakthrough, the gravitational waves were detected on Sept. 14, 2015 by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington.

Based on the observed signals, LIGO scientists estimate that the black holes for this event were about 29 and 36 times the mass of the sun, and the event took place 1.3 billion years ago. About three times the mass of the Sun was converted into gravitational waves in a fraction of a second — with a peak power output about 50 times that of the whole visible universe.

By looking at the time of arrival of the signals — the detector in Livingston recorded the event 7 milliseconds before the detector in Hanford — scientists can say that the source was located in the Southern Hemisphere.

Related: New star puts on a show in stunning image

According to general relativity, a pair of black holes orbiting around each other lose energy through the emission of gravitational waves, causing them to gradually approach each other over billions of years, and then much more quickly in the final minutes. In a final fraction of a second, the two black holes collide and form one massive black hole. A portion of their combined mass is converted to energy, according to Einstein’s formula E=mc2, and this energy is emitted as a final strong burst of gravitational waves.

These are the gravitational waves that LIGO observed.

“With this discovery, we humans are embarking on a marvelous new quest: the quest to explore the warped side of the universe — objects and phenomena that are made from warped spacetime. Colliding black holes and gravitational waves are our first beautiful examples,” Caltech’s Kip Thorne said.

 

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February 1, 2016

Surprise! Monster Black Hole Found in Dwarf Galaxy

Filed under: Big Bang, Black Holes, Cool — bferrari @ 11:10 am

Size doesn’t matter…

This image shows a huge galaxy, M60, with the small dwarf galaxy that is expected to eventually merge with it. (NASA/Space Telescope Science Institute/European Space Agency)

This image shows a huge galaxy, M60, with the small dwarf galaxy that is expected to eventually merge with it. (NASA/Space Telescope Science Institute/European Space Agency)

Astronomers have just discovered the smallest known galaxy that harbors a huge, supermassive black hole at its core.

The relatively nearby dwarf galaxy may house a supermassive black hole at its heart equal in mass to about 21 million suns. The discovery suggests that supermassive black holes may be far more common than previously thought.

A supermassive black hole millions to billions of times the mass of the sun lies at the heart of nearly every large galaxy like the Milky Way. These monstrously huge black holes have existed since the infancy of the universe, some 800 million years or so after the Big Bang. Scientists are uncertain whether dwarf galaxies might also harbor supermassive black holes. [Watch a Space.com video about the new dwarf galaxy finding]

“Dwarf galaxies usually refer to any galaxy less than roughly one-fiftieth the brightness of the Milky Way,” said lead study author Anil Seth, an astronomer at the University of Utah in Salt Lake City. These galaxies span only several hundreds to thousands of light-years across, much smaller than the Milky Way’s 100,000-light-year diameter, and they “are much more abundant than galaxies like the Milky Way,” Seth said.

The researchers investigated a rarer kind of dwarf galaxy known as an ultra-compact dwarf galaxy; such galaxies are among the densest collections of stars in the universe. “These are found primarily in galaxy clusters, the cities of the universe,” Seth told Space.com.

This is an illustration of the supermassive black hole located in the middle of the very dense galaxy M60-UCD1. It weighs as much as 21 million times the mass of our Sun. Lying about 50 million light-years away, M60-UCD1 is a tiny galaxy with a diameter of 300 light-years — just 1/500th of the diameter of the Milky Way! Despite its size it is pretty crowded, containing some 140 million stars. Because no light can escape from the black hole, it appears simply in silhouette against the starry background. The black hole’s intense gravitational field warps the light of the background stars to form ring-like images just outside the dark edges of the black hole’s event horizon. Combined observations by the NASA/ESA Hubble Space Telescope and NASA’s Gemini North telescope determined the presence of the black hole inside M60-UCD1.

This is an illustration of the supermassive black hole located in the middle of the very dense galaxy M60-UCD1. It weighs as much as 21 million times the mass of our Sun. Lying about 50 million light-years away, M60-UCD1 is a tiny galaxy with a diameter of 300 light-years — just 1/500th of the diameter of the Milky Way! Despite its size it is pretty crowded, containing some 140 million stars. Because no light can escape from the black hole, it appears simply in silhouette against the starry background. The black hole’s intense gravitational field warps the light of the background stars to form ring-like images just outside the dark edges of the black hole’s event horizon. (Combined observations by the NASA/ESA Hubble Space Telescope and NASA’s Gemini North telescope determined the presence of the black hole inside M60-UCD1.)

Now, Seth and his colleagues have discovered that an ultra-compact dwarf galaxy may possess a supermassive black hole, which would make it the smallest galaxy known to contain such a giant.

The astronomers investigated M60-UCD1, the brightest ultra-compact dwarf galaxy currently known, using the Gemini North 8-meter optical-and-infrared telescope on Hawaii’s Mauna Kea volcano and NASA’s Hubble Space Telescope. M60-UCD1 lies about 54 million light-years away from Earth. The dwarf galaxy orbits M60, one of the largest galaxies near the Milky Way, at a distance of only about 22,000 light-years from the larger galaxy’s center, “closer than the sun is to the center of the Milky Way,” Seth said.

The scientists calculated the size of the supermassive black hole that may lurk inside M60-UCD1 by analyzing the motions of the stars in that galaxy, which helped the researchers deduce the amount of mass needed to exert the gravitational field seen pulling on those stars. For instance, the stars at the center of M60-UCD1 zip at speeds of about 230,000 mph (370,000 km/h), much faster than stars would be expected to move in the absence of such a black hole.

The supermassive black hole at the core of the Milky Way has a mass of about 4 million suns, taking up less than 0.01 percent of the galaxy’s estimated total mass, which is about 50 billion suns. In comparison, the supermassive black hole that may lie in the core of M60-UCD1 appears five times larger than the one in the Milky Way, and also seems to make up about 15 percent of the dwarf galaxy’s mass, which is about 140 million suns.

“That is pretty amazing, given that the Milky Way is 500 times larger and more than 1,000 times heavier than the dwarf galaxy M60-UCD1,” Seth said in a statement.

Astronomers have debated the nature of ultra-compact dwarf galaxies for years — whether they were extremely massive clusters of stars that were all born together, or whether they were the centers or nuclei of large galaxies that had their outer layers stripped away during collisions with other galaxies. These new findings hint that ultra-compact dwarf galaxies are the stripped nuclei of larger galaxies, because star clusters do not host supermassive black holes.

The researchers suggest M60-UCD1 was once a very large galaxy, with maybe 10 billion stars, “but then it passed very close to the center of an even larger galaxy, M60, and in that process, all the stars and dark matter in the outer part of the galaxy got torn away and became part of M60,” Seth said in a statement. “That was maybe as much as 10 billion years ago. We don’t know.”

Eventually, M60-UCD1 “may merge with the center of M60, which has a monster black hole in it, with 4.5 billion solar masses — more than 1,000 times bigger than the supermassive black hole in our galaxy,” Seth said in a statement. “When that happens, the black hole we found in M60-UCD1 will merge with that monster black hole.”

The astronomers suggest the way stars move in many other ultra-compact dwarf galaxies hints that they may host supermassive black holes, as well. All in all, the scientists suggest that ultra-compact dwarf galaxies could double the number of supermassive black holes known in the nearby regions of the universe. The researchers are participating in ongoing projects that may provide conclusive evidence for supermassive black holes in four other ultra-compact dwarfs.

The scientists detailed their findings in the Sept. 18 issue of the journal Nature.

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Monster Galaxy Cluster Is Biggest Ever in the Early Universe

Filed under: Big Bang, Black Holes, Cool — bferrari @ 10:54 am
This image of the massive galactic cluster IDCS 1426 combines data taken by three major NASA telescopes. The off-center core of X-rays is shown in blue-white near the middle of the cluster, and was captured by Chandra. Visible light from the Hubble Space Telescope is green, and infrared light from Spitzer is shown in red.

This image of the massive galactic cluster IDCS 1426 combines data taken by three major NASA telescopes. The off-center core of X-rays is shown in blue-white near the middle of the cluster, and was captured by Chandra. Visible light from the Hubble Space Telescope is green, and infrared light from Spitzer is shown in red. (NASA, ESA, and M. Brodwin (University of Missouri))

KISSIMMEE, Fla. ─ The most massive collection of galaxies in the early universe has been spotted. Although not the largest collection of galaxies ever found, it holds the record as the largest group in the early universe, appearing surprisingly old for the time.

“Of all the structures we’ve ever seen, this is the most massive in the first 4 billion years of the universe,” astronomer Mark Brodwin, of the University of Missouri at Kansas City, said at a news conference unveiling the discovery here at the 47th annual meeting of the American Astronomical Society. Brodwin led the team that identified the evolved ancient galaxy cluster.

“It should be consistent with the largest cluster in the observable universe.” [The History and Structure of the Universe in Images]

Galaxy clusters are collections of galaxies that formed once stars and individual galaxies had been built. Gravity binds hundreds of thousands of galaxies together in collections so large, they can distort the fabric of space-time. According to present understanding, the massive objects should take billions of years to form.

In 2012, scientists used NASA’s Spitzer Space Telescope to measure the galactic cluster IDCS 1426, which lies approximately 10 billion light-years from Earth. Because light takes a full year to travel the distance of 1 light-year, that means astronomers are able to study the cluster as it appeared when the universe was only 3.8 billon years old. [Related: How Old Is the Universe?]

Initial estimates suggested that IDCS 1426 contained an enormous mass at a significant distance, but were not conclusive. Brodwin and his colleagues decided to use NASA’s Hubble Space Telescope, Keck Observatory and Chandra X-ray Observatory to refine measurements of the mass of the cluster, using three different methods.

Hubble and Keck studied IDCS 1426 in optical light. Because clusters bend space-time, they are frequently used as natural magnifying glasses to observe objects behind the cluster in a process known as gravitational lensing. A more massive cluster produces a higher gravitational force that bends the light more strongly; by observing how the light traveled around the cluster, the scientists could calculate its weight.

At the same time, Chandra studied the object in the X-ray wavelength. The more massive a galaxy cluster is, the more the gas within it is compressed and heated, producing more X-rays. By observing those X-rays, the scientists were able to compute the mass of the cluster.

All three observations independently provided a mass 250 trillion times higher than the mass of the sun, or 1,000 times more massive than the Milky Way.

IDCS 1426 is not the most massive galaxy cluster in the universe. That distinction is held by a massive cluster that lies only 7 billion light-years from Earth. Known informally as ‘El Gordo,’the hefty cluster weighs in at a whopping 3 quadrillion times the mass of the sun (that’s 3 followed by 15 zeros, or one thousand million million). However, according to Brodwin, the cluster is on track to grow into something that large.

“Statistically speaking, it is a progenitor of ‘El Gordo,'” he said.

After another 3 billion years, the ancient collection should weigh in fairly close to the larger cluster.

The research will be published in The Astrophysical Journal, though a preprint of the study is available on the site Arxiv.org.

The enormous mass of IDCS 1426 in the early in the life of the universe isn’t the only indication of its unusual evolution. In addition to studying its mass, Chandra also took the temperature of the heart of the distant cluster, and found something surprising.

The core of a galactic cluster is an active place, with objects moving around and bumping into one another. This ongoing activity keeps the core hot for the cluster’s early lifetime. Once things slow down, however, conditions in the core begin to relax, and the center begins to release energy in the form of X-rays, causing the center to slowly cool.

Chandra revealed a bright knot of X-rays at the center of IDCS 1426 that were surprisingly cool. In fact, it is the first “cool core” cluster at such an early age in the universe. The cool heart of the cluster provides even more evidence for its formation early in the life of the universe.

“A cool core is a property of an evolved cluster,” Brodwin said.

A collision may have added the extra kick to the formation of the young cluster. The cool core lies not in the center of the IDCS 1426 but off to one side by a few hundred thousand light-years.

“When it is hit by another group or cluster, the cool core will slosh around like wine in the bottom of the wine glass,” Brodwin said.

“Eventually it will settle towards the center, but it hasn’t settled yet.”

All of these suggest an advanced age for the cluster that came as a surprise for a feature so early in the life of the universe.

“The cluster looks at least a billion years old,” Brodwin said.

“It probably really started forming 2 to 3 billion years earlier, which is very early for something of that size.”

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January 16, 2016

Astronomers may have found most powerful supernova

Filed under: Big Bang, Black Holes, Cool, Cosmology, Gamma Ray Bursts, Supernova — bferrari @ 4:51 pm
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Enter a caption

  • “This may be the most powerful supernova ever seen by anybody,” Ohio State University professor says

An international team of astronomers may have discovered the biggest and brightest supernova ever.

The explosion was 570 billion times brighter than the sun and 20 times brighter than all the stars in the Milky Way galaxy combined, according to a statement from The Ohio State University, which is leading the study. Scientists are straining to define its strength.

“This may be the most powerful supernova ever seen by anybody … it’s really pushing the envelope on what is possible,” study co-author Krzysztof Stanek, an astronomer at Ohio State, was quoted as saying in The Los Angeles Times.

The team of astronomers released their findings this week in the journal Science. The explosion and a gas cloud that resulted are called ASASSN-15lh after the team of astronomers, All Sky Automated Survey for Supernovae, that discovered it last June.

A supernova is a rare and often dramatic phenomenon that involves the explosion of most of the material within a star. Supernovas can be very bright for a short time and usually release huge amounts of energy.

Searching for the power source

This blast created a massive ball of hot gas that the astronomers are studying through telescopes around the world, Ohio State said. It cannot be seen with the naked eye because it is 3.8 billion light years from Earth.

There’s an object about 10 miles across in the middle of the ball of gas that astronomers are trying to define.

“The honest answer is at this point that we do not know what could be the power source for ASASSN-15lh,” said Subo Dong, lead author of the Science paper, according to Ohio State. He is a Youth Qianren Research Professor of astronomy at the Kavli Institute for Astronomy and Astrophysics at Peking University.

Todd Thompson, professor of astronomy at Ohio State, said the object in the center may be a rare type of star called a millisecond magnetar. Spawned by a supernova, it’s a rapidly spinning, dense star with a powerful magnetic field.

Could it be a ‘supermassive black hole’?

To achieve the brightness recorded, the magnetar would have to spin 1,000 times a second and “convert all that rotational energy to light with nearly 100% efficiency,” Thompson said, according to the Ohio State press release. “It would be the most extreme example of a magnetar that scientists believe to be physically possible.”

The question of whether a suprnova truly caused the space explosion may be settled later this year with help from the Hubble Space Telescope, which will allow astronomers to see the host galaxy surrounding the object in center of the ball of gas, Ohio State said.

If it’s not a magnetar, it may be unusual nuclear activity around “a supermassive black hole,” Ohio State said.

Source

June 10, 2014

Space oddity: Bizarre hybrid star found after 40-year search

Filed under: Black Holes, Cool, Cosmology, Supernova — bferrari @ 7:08 am
Image showing the location of the star HV 2112 — a hybrid between a red supergiant and a neutron star — in the Small Magellanic Cloud, a dwarf galaxy that lies about 200,000 light-years from Earth.Phil Massey, (Lowell Observatory)

Image showing the location of the star HV 2112 — a hybrid between a red supergiant and a neutron star — in the Small Magellanic Cloud, a dwarf galaxy that lies about 200,000 light-years from Earth.Phil Massey, (Lowell Observatory)

Astronomers have apparently discovered the first of a class of strange hybrid stars, confirming theoretical predictions made four decades ago.

In 1975, physicist Kip Thorne and astronomer Anna Zytkow proposed the existence of odd objects that are hybrids between red supergiants and neutron stars — the collapsed, superdense remnants of supernova explosions.

These so-called Thorne-Zytkow objects (TZOs) likely form when a red supergiant gobbles up a nearby neutron star, which sinks down into the giant’s core, researchers said. TZOs look like ordinary red supergiants, like the famed star Betelgeuse in the constellation Orion, but differ in their chemical fingerprints, the theory goes. [Top 10 Star Mysteries]

“Studying these objects is exciting because it represents a completely new model of how stellar interiors can work,” study leader Emily Levesque, of the University of Colorado Boulder, said in a statement.

“In these interiors we also have a new way of producing heavy elements in our universe,” she added. “You’ve heard that everything is made of ‘star stuff’ — inside these stars we might now have a new way to make some of it.”

And now Levesque and her team say they have probably found the first TZO — a star called HV 2112 in the Small Magellanic Cloud, a dwarf galaxy that lies about 200,000 light-years away.

The researchers used the 6.5-meter Magellan Clay telescope in Chile to study the light emitted by HV 2112. They found the starlight to be highly enriched in rubidium, lithium and molybdenum, just as theory predicts for TZOs. (Normal red supergiants produce these elements as well, but not in such abundance, scientists said.)

The new data, while suggestive, do not represent a slam-dunk discovery for TZOs quite yet, researchers said.

“We could, of course, be wrong,” co-author Philip Massey, of Lowell Observatory in Flagstaff, Arizona, said in a statement.

“There are some minor inconsistencies between some of the details of what we found and what theory predicts,” he added. “But the theoretical predictions are quite old, and there have been a lot of improvements in the theory since then. Hopefully our discovery will spur additional work on the theoretical side now.”

The find means a lot to Zytkow, who is a co-author of the new study.

“I am extremely happy that observational confirmation of our theoretical prediction has started to emerge,” said Zytkow, who is based at the University of Cambridge in England. “Since Kip Thorne and I proposed our models of stars with neutron cores, people were not able to disprove our work. If theory is sound, experimental confirmation shows up sooner or later. So it was a matter of identification of a promising group of stars, getting telescope time and proceeding with the project.”

The study has been accepted for publication in the Monthly Notices of the Royal Astronomical Society Letters.

Source

May 28, 2014

21-year-old makes astronomy breakthrough

Filed under: Black Holes, Cool, Cosmology, Outer Solar System — bferrari @ 11:53 am
This stock photo shows a dense swarm of stars. (AP PHOTO/NASA-ESA)

This stock photo shows a dense swarm of stars. (AP PHOTO/NASA-ESA)

At just 21 years old, a California college student has made an incredible discovery: Michael Sandoval and his astrophysics professor at San Jose State have spotted what they believe is one galaxy that was swallowed up by another.

The result is a dense system of stars—apparently the densest ever found. They’re calling it a “hypercompact cluster,” since no word for the object currently exists, theSan Jose Mercury News reports.

The finding occurred as Sandoval took the first course he’d ever taken on the subject, NBC Bay Area reports. “Some people take years and never find” such space phenomena, says astrophysics professor Aaron Romanowsky.

Sandoval took about a week to find it, inspired by the work of a classmate who’d found what had previously appeared to be the densest known bunch of stars.

To make the story even more impressive, Sandoval’s find came as he grieved for his mother, who died in October. He’d been living at home in recent years to take care of her during an illness, sometimes having to take her to the ER before heading to class the next day.

“I didn’t want to be sitting home, feeling sorry for myself,” Sandoval says. “That’s not what she would have wanted, anyway.” (Another recent space discovery involves an ancient space collision.)

Source

May 23, 2014

Supernova discovery reveals how the biggest, brightest stars die

Filed under: Black Holes, Cool, Gamma Ray Bursts — bferrari @ 11:28 am
A brilliant supernova (right) explodes in the galaxy UGC 9379, located about 360 million light-years from Earth, in this before-and-after view. The left image was taken by the Sloan Digital Sky Survey, while the right image was obtained with aAVISHAY GAL-YAM, WEIZMANN INSTITUTE OF SCIENCE

A brilliant supernova (right) explodes in the galaxy UGC 9379, located about 360 million light-years from Earth, in this before-and-after view. The left image was taken by the Sloan Digital Sky Survey, while the right image was obtained with aAVISHAY GAL-YAM, WEIZMANN INSTITUTE OF SCIENCE

The most massive and luminous stars were long suspected to explode when they die, and astronomers now have the most direct evidence yet that these cosmic behemoths go out with a bang.

These findings shed light on the star explosions that provide the universe with the ingredients for planets and life, the researchers added.

With a mass more than 330,000 times that of Earth, the sun accounts for 99.86 percent of the solar system’s total mass. But as stars go, the sun is a lightweight. The largest and most luminous stars in the universe are Wolf-Rayet stars, which are more than 20 times as massive as the sun and at least five times as hot. Only a few hundred of these titan stars are known to astronomers.

[Biggest Star Mysteries of All Time]

The intense heat of Wolf-Rayet stars forces their matter apart, making them extraordinarily windy stars. They usually lose the mass equivalent to that of the Earth each year, blowing winds at up to 5.6 million mph.

How giant stars die

Astronomers long suspected that Wolf-Rayet stars violently self-destructed as supernovas, the most powerful stellar explosions in the universe. These outbursts are bright enough to momentarily outshine their entire galaxies, and enrich galaxies with heavy elements that eventually become the building blocks for planets and life.

However, the gigantic amounts of matter these stars blow out usually obscure them completely, so scientists weren’t sure how they form, live and die.

“Finding what kind of star exploded, after it already exploded, is, of course, a hard problem, since the explosion destroys much of the information,” said study author Avishay Gal-Yam, an astrophysicist at the Weizmann Institute of Science in Israel.

Some researchers even raised doubts as to whether Wolf-Rayet stars detonated as supernovas at all. “Some modelers predict that massive Wolf-Rayet stars will collapse into a black hole ‘quietly,’ without making a luminous supernova,” Gal-Yam told Space.com.

Now, for the first time, scientists have direct confirmation that a Wolf-Rayet star died in a supernova. They detail their findings in the May 22 issue of the journal Nature.

The researchers focused on a supernova named SN 2013cu, which exploded about 360 million light-years away from Earth in the Bootes constellation. This explosion was a Type IIb supernova, meaning it took place after the core of its star ran out of fuel, collapsing into an extraordinarily dense nugget in a fraction of a second and rebounding with a blast outward. What is left over after such supernovas is either a neutron star or a black hole.

A Wolf-Rayet smoking gun

By surveying the sky with the intermediate Palomar Transient Factory (iPTF), a project that charts the sky with a telescope mounted with a robotic observing system, the researchers discovered the supernova very soon after it happened.

“We now send high-quality supernova alerts to astronomers all around the globe in less than 40 minutes,” said study co-author Peter Nugent, a researcher at the University of California, Berkeley.

The scientists next rallied ground- and space-based telescopes across the world to observe the infant supernova approximately 5.7 hours and 15 hours after it detonated.

“Newly developed observational capabilities now enable us to study exploding stars in ways we could only dream of before,” Gal-Yam said. “We are moving towards real-time studies of supernovae.”

The explosion ionized surrounding molecules in an ultraviolet flash, giving them an electric charge. The ionized material that surrounded the star emits light that “tells us the elemental composition of the wind, and hence the surface composition of the star as it was just before it exploded,” Gal-Yam said. “That is a very powerful clue about the nature of the exploding star and how it evolved before it exploded, and this is the first time we managed to get this information.”

That opportunity lasts only for a day before the supernova blast wave sweeps the ionization away, Gal-Yam added.

This light suggested the precursor of the supernova was a nitrogen-rich Wolf-Rayet star. “This is the smoking gun,” Nugent said. “For the first time, we can directly point to an observation and say that this type of Wolf-Rayet star leads to this kind of Type IIb supernova.”

“When I identified the first example of a Type IIb supernova in 1987, I dreamed that someday we would have direct evidence of what kind of star exploded,” said study co-author Alex Filippenko, a researcher at the University of California, Berkeley. “It’s refreshing that we can now say that Wolf-Rayet stars are responsible, at least in some cases.”

Future studies could analyze more Wolf-Rayet stars, to see if these violent deaths are standard for them.

“If we can show that this is the norm for such massive stars, it would mean that new theories will have to be developed to explain how you can make a black hole and still throw out a lot of material and a lot of energy to make a luminous supernova,” Gal-Yam said.

Source

February 13, 2014

National Ignition Facility announces promising results for nuclear fusion

Filed under: Big Bang, Black Holes, Cool, Gadgets, The Sun — bferrari @ 8:44 am
A deuterium and tritium capsule, sphere in window at center, inside a cylindrical hohlraum container about 0.4 inches tall. In research reported Wednesday, Feb. 12, 2014 by the journal Nature, scientists say they've taken a key step toward harnessing nuclear fusion as a new way to generate power. (AP PHOTO/LAWRENCE LIVERMORE NATIONAL LABORATORY, EDDIE DEWALD)

A deuterium and tritium capsule, sphere in window at center, inside a cylindrical hohlraum container about 0.4 inches tall. In research reported Wednesday, Feb. 12, 2014 by the journal Nature, scientists say they’ve taken a key step toward harnessing nuclear fusion as a new way to generate power. (AP PHOTO/LAWRENCE LIVERMORE NATIONAL LABORATORY, EDDIE DEWALD)

NEW YORK – Scientists say they’ve taken a key step toward harnessing nuclear fusion as a new way to generate power, an idea that has been pursued for decades.

They are still a long way from that goal. The amount of energy they got out of their experimental apparatus was minuscule compared to what they put into it.

Still, the new work reached some significant milestones along the path to a cleaner and cheaper source of electricity, the researchers and experts said.

Fusion is the merging of hydrogen atoms, the process that powers the sun. That’s different from nuclear fission, which is the breaking apart of atoms that lies at the heart of today’s nuclear power plants.

Both processes release energy, but scientists have been pursuing fusion power because of several advantages. The supply of hydrogen for fuel is virtually unlimited, available from seawater, for example, in contrast to the uranium used in nuclear power plants. Fusion power would avoid the need for long-term storage of radioactive waste. And unlike fossil fuels like coal, it would not produce greenhouse gases that cause global warming.

In the new work, reported online Wednesday by the journal Nature, scientists from the Lawrence Livermore National Laboratory near San Francisco, report results from two experiments done at the lab’s National Ignition Facility

In each trial, 192 laser beams briefly fired into a half-inch-long gold cylinder. The cylinder held a tiny ball that contained the fuel, which was a mix of two kinds of hydrogen, called deuterium and tritium. The energy from the lasers kicked off a process that compressed the ball by an amount akin to squeezing a basketball down to the size of a pea, said Debbie Callahan, an author of the paper.

A cylindrical hohlraum container about 0.4 inches tall containing a deuterium and tritium capsule, held by cryogenically-cooled positioning arms. In research reported Wednesday, Feb. 12, 2014 by the journal Nature, scientists say they've taken a key step toward harnessing nuclear fusion as a new way to generate power. (AP PHOTO/LAWRENCE LIVERMORE NATIONAL LABORATORY, EDDIE DEWALD)

A cylindrical hohlraum container about 0.4 inches tall containing a deuterium and tritium capsule, held by cryogenically-cooled positioning arms. In research reported Wednesday, Feb. 12, 2014 by the journal Nature, scientists say they’ve taken a key step toward harnessing nuclear fusion as a new way to generate power. (AP PHOTO/LAWRENCE LIVERMORE NATIONAL LABORATORY, EDDIE DEWALD)

That created the extremely high pressure and temperatures needed to get the hydrogen atoms to fuse. It was all over in the blink of an eye, with the reaction confined to a space smaller than the width of a human hair.

Nuclear fusion would be worthwhile only if it produces more energy than it uses, and the results were far from that. The hydrogen fuel did emit more energy than it absorbed from the lasers, an experimental goal. But the fuel took in only about 1 percent of all the energy produced by the lasers. So the apparatus is still far short of producing more energy than it requires to operate.

Another key finding was evidence that energy created by the fusion reaction was going back into the remaining fuel, a “bootstrapping” process that is key to boosting the energy output.

“Seeing that kick in is quite exciting, and it does show that there is promise” for increasing the energy output, said Omar Hurricane, lead author on the Nature paper. It’s not clear when researchers will be able to get more energy out of the reaction than the lasers pour into it, he said, but “we are working like mad … in that direction.”

The sign of bootstrapping is “really a wonderful result,” said fusion expert Robert McCrory of the University of Rochester, who was not involved in the research. “There’s a lot more that needs to be done” to reach the point where the reaction produces more energy than the lasers deliver, but “this was absolutely necessary.”

Scientists elsewhere are working on a different approach to fusion power, one that uses magnetic fields to contain super-heated hydrogen fuel. Several nations are cooperating to build a huge experimental device to explore that approach in France.

Source

February 10, 2014

Australian scientists discover oldest known star

Filed under: Big Bang, Black Holes, Cool, Cosmology — bferrari @ 3:03 pm

Stefan-Keller-and-Mike-Bessell_1600

A team of Australian astronomers say they have identified the oldest known star in our universe — one that formed a mere 200 million years after the Big Bang.

“This is the first time that we’ve been able to unambiguously say that we’ve found the chemical fingerprint of a first star,” lead researcher, Stefan Keller of the Australian National University (ANU) research school of astronomy and astrophysics said in a press release.

The star, named SMSS J031300.36-670839.3, is estimated to be 13.6 billion years old and is much older than previous stars found in 2007 and 2013, which were believed to be 13.2 billion years old.

The astronomers analyzed the light from the star to determine its chemical makeup, and extrapolated its age from there.

‘This is the first time that we’ve been able to unambiguously say that we’ve found the chemical fingerprint of a first star.’

– astronomer Stefan Keller

“The telltale sign that the star is so ancient is the complete absence of any detectable level of iron in the spectrum of light emerging from the star,” explained Keller.

The star was first spotted on January 2 in the Milky Way, 6,000 light years away from the Earth using the ANU Skymapper telescope.

“The stars we are finding number one in a million,” team member Professor Mike Bessel said in a press release. “Finding such needles in a haystack is possible thanks to the ANU SkyMapper telescope that is unique in its ability to find stars with low iron from their color.”

The newly discovered star was formed in the wake of a primordial star and had a mass 60 times that of our Sun.

“To make a star like our Sun, you take the basic ingredients of hydrogen and helium from the Big Bang and add an enormous amount of iron – the equivalent of about 1,000 times the Earth’s mass,” Keller said.

Keller explained that primordial stars were previously thought to have died in violent explosions which polluted space with iron. But his discovery shows signs of pollution of lighter elements like carbon and magnesium with no traces of iron.

“To make this ancient star, you need no more than an Australia-sized asteroid of iron and lots of carbon,” Keller continued. “It’s a very different recipe that tells us a lot about the nature of the first stars and how they died.”

Keller and his team hope that their discovery will help resolve long-standing discrepancies between observations and predictions of the Big Bang.

“This is one of the first steps in understanding what those first stars were like,” said Keller. “What this star has enabled us to do is record the fingerprint of those first stars.”

The discovery was published in the latest edition of the journal Nature.

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